Currently, the required illumination distance of a street lamp is at least 75 m, while a light-distribution deflection angle of an optical lens or a reflecting cup is insufficient, therefore, the existing LED high-pole lamps for plaza illumination are often mounted at a large elevation angle, and light emitted from the LED high-pole lamps can be projected onto the ground opposite to a lamp pole. In addition, a large amount of light emitted from the LED high-pole lamps is directly projected to the sky, causing light pollution.
The LED high-pole lamps for plaza illuminations often have high powers and, meanwhile, a large number of lamps are required to be circumferentially mounted on one lamp pole within 360 degrees. Thus, strong glare is often generated by the high-pole lamps and directly emitted to the sky, which adversely affects airplanes flying at high altitudes. For example, pilots may erroneously identify it as navigation lights. Further, the strong light emitted to the sky illuminates the clouds, forming noisy background light and blocking the starlight. Accordingly, the primary color of the night sky is changed, and the quiet atmosphere of the night is weakened.
Further, secondary optical lenses of the existing LED street lamps for road illumination are substantially designed to meet the requirement of 2-5 lanes, i.e., illuminate 2-5 lanes. In a direction vertical to the road, the deflection angles of the optical lenses are substantially within the range of 30 to 50 degrees. Due to the insufficient deflection angles, the light emitted by the optical lenses cannot reach as far as 6-7 lanes, thus fails to meet the road illumination requirement of 6-7 lanes.
The disclosed methods and devices are directed to solve one or more problems set forth above and other problems.